I'm doing a blanket with a built-in garter stitch border -- knit first 6 and last 6 stitches of every row. What stitch should I do to start each row to get the best look? If I follow the pattern and just knit, I get the little bumps on the vertical selvedge. If I bring the yarn in front and purl slip the first stitch of every row I get a nice chain edge. But I worry that it will not be a "tight" edge and will loosen up with time. I won't be adding more border or sewing a seam, so I don't need the chain edge to pick up stitches, I just think it looks better.

Any other suggestions/tips? All the websites just talk about clean edges on stockinette stitch. Thanks!!

Yup, I usually slip my first stitch as well - I love the edge it gives my projects. What I learned on a scarf pattern I made a while back was that if the first stitch presented itself as a knit stitch, slip it with yarn in back as a knit stitch. If the first stitch presents itself as a purl stitch, slip it with yarn in front as a purl stitch. I haven't really played around with other variations, but I'm really happy with my edges when I follow that guideline.